1. Field of the Invention
The present invention relates to a transmission which has in combination a speed reducer, a planetary drive, and a brake which gradually slows and stops a wheel member of the planetary drive and varies the output speed of the transmission.
2. Description of the Prior Art
The American U.S. Pat. No. 1,732,405 discloses a motor transmission unit which has an engine charging compressor for controlling the speed of a wheel member of a bevel gear type of planetary drive. The compressors resistance then varies the output speed of the transmission. This design is not efficient since it lacks a means for gradually stopping the planetary drive wheel member. The motor transmission unit is complex and does not have a simple brake which gradually slows the planetary wheel member. It also requires the addition of a separate clutch.
The American U.S. Pat. No. 4,973,295 discloses a stepless variable ratio transmission which has a worm gear assembly for controlling the speed of a wheel member of a conventional type of planetary drive. A stepping motor controls the speed of the worm and varies the speed of the transmission. This design has the disadvantage of being complex with the worm gear assembly and stepping motor. Also additional power to operate the stepping motor is required.
Furthermore, neither of the aforementioned Patents provides insights or practical solutions for reverse drive.